Fuse.



PATENTED MAY 31,; 1904.

w. MQELROY.

FUSE.

APPLICATION rnsn APR. 2, 1900.

3 SHEETS-SHEET 1.

N0 MODEL.

FIG. 7.

FIG, 2.

INVENTOR: 7%

By Attorneys, [g

PATENTED MAY 31, 1904.

W. MQELROY.

FUSE.

APPLIOATION FILED APR. 2, 1000.

3 SHEETS-SHEET 2.

NO MODEL.

WITNESSES Z M v WASHKNGTON u c m: gums PETERS c PATENTED MAY 31, 1904.

W. MoBLROY.

FUSE.

APPLICATION FILED APR. 2, 1900.

3 SHEETS-SHEET 3.

N0 MODEL.

INVENTOR:

By Ag'zarneys,

a W W.

UNiTan STATES Patented May 31, 1904.

PATENT OFFICE.

WVILLIAM MoELROY, OF BROOKLYN, NEW YORK, ASSIGNOR OF TWO- THIRDS TO GEORGE A. MOELROY AND GEORGE HOLT FRASER, OF

BROOKLYN, NEW YORK.

FUSE.

SPECIFICATION forming part of Letters Patent No. 761,094, dated May 31, 1904;.

Application filed April 2, 1900. Serial No. 11,070- (No model.)

cause the local circuit becomes overloaded.

Such fuses have consisted of an individual wire of easily-fusible metal, and when the fuse has been burned out it has been necessary to substitute a new fuse to restore the local circuit. In house lighting systems and in trolley-cars it frequently happens that a momentary short circuit or temporary overloading burns out a fuse, thus rendering the local circuit inoperative until a new fuse-wire can be placed in position. In some cases a permanent short circuit of the local circuit will immediately cause burning out of the new wire before the fact of permanent short circuit is discovered. It is usually'a source of much inconvenience and delay to manually replace a fuse-wire after one has burned out, and in case of a permanent short circuit there is some danger in placing the new fuse, which will be immediately burned out before the user discovers that there is a permanent short circuit.

My invention aims to provide novel means for automatically connecting a plurality of fuses successively in the line so thataline will be automatically completed after the burning out of the fuse, and it also aims to provide means for automatically indicating the fact when there is a permanent short circuit. To this end in carrying out the preferred form of my invention I provide a plurality offn'ses and means controlled by the current for successively connecting them with the terminals of an electric conductor and preferably, also, means for preventing their connection after a predetermined number of fuses have been burned out. One or both the electric terminals or the successive fuses may be movable, so that a fuse will automatically be connected after a preceding one has been burned out. Preferably the fuse-wires are stationary, and one of the electric-terminals is movable into contact with several other terminals, each connected to the line by an individual fuse. able means for moving the movable part as a clockwork or electromagnet may be employed, and the fuse may be used to hold its terminal in contact with the movable terminal until the fuse is burned out, whereupon its terminal can move to free the movable terminal and allow the latter to make electrical connection with the terminal of an adjacent fuse. I prefer to arrange these terminals in circuit and revolve the movable terminal on an axis concentric with this circuit. 1 also prefer to provide means for arresting the movable terminal between two fuse-terminals after, say, two of the latter have been burned out, so that the operator will know by the position of the movable terminal that there is a permanent short circuit. I also prefer to provide means automatically preventing a completion of the local circuit after burning out, except at a Suitsuitable delay or interval of time thereafter I or when the switch controlling the circuit is in a suitable or a predetermined position or when there is a predetermined condition of the local circuit. These various features may be provided in whole or in part, according to any suitable manner which circumstances or the judgment of those skilled in the art may dictate, without departing from the spirit of my invention, and as illustrating certain adaptations thereof I will refer to the accompanying drawings and describe in detail the adaptations therein shown.

Figure 1 is a plan view showing the preferred form of my invention. Fig. 2 is a side elevation thereof. Fig. 3 is a diagrammatic plan thereof, showing the mechanism below the fuse-board in the position for closing a burned-out circuit. Fig. 4c is a similar fragmentary view showing the'position of the opcrating mechanism when the circuit is restored. Fig. 5 is a fragmentary planshowing, on a large scale, a modification; and Fig. 6 is a fragmentary vertical section thereof cut in the planes of the lines 6 6, Fig. 5, and looking in the direction of the arrows.

Referring to the drawings, let A indicate one conductor, and B the other conductor, of the main line of any electric circuit, as a trolley-line, for example; (1, a local circuit fed from such line; a, 7), c, and (l, conductors of the local circuit; 1), a switch or resistance-box therefor; E, the controller-contact thereof connected to thewire I); c, the resistance-contacts thereof connected with the wire a; F. a motor in the local circuit, and G represents lamps in such circuit. It is usual in such circuits to interpose a fuse or automatic cut-out at some point in the local circuit to protect the latter against overloading. I prefer to provide a plurality of fuses or protective pro visions and to make either the fuses or the contact terminals, or both, movable to connect a new fuse after an old one has burned out, or means to automatically break a circuit and automatically renew it.

In the example shown the wire 5 is connected to a binding-post f, having a plurality of fixed terminals g g to g arranged in a circuit, and a fuse-wire I is connected to each terminal, and there is a plurality of terminals J J to J, each movable and each connected by its fuse-wire to a corresponding terminal of the wire I) and each adapted to be connected to the wire 0 by a movable contact H, connected to the binding-post h of the wire 0. In this way the circuit extends through one fuse and the contact H from the wire 6 to the wire a, and when that fuse is burned out the contact H can be moved into contact with the next one of the terminals J, and thus will close the circuit through the succeeding fuse. The movable part may be moved in any way from any source of power and with any speed; but I prefer to move it by power controlled by the position of the switch controlling the local circuit. This can be variously done; but I prefer the construction shown best in Fig. 3, in which I use a shunt-wire leading from the wire a to a rheotome or other electromagneticpower device K, from which I lead a wire 7' to the switch-box D, where it terminates in a contact if; in proximity to another contact Z, both of which are in position to be electrically connected by the controller E when the latter is in the inoperative position, in which the motor F is cut out, the wire m from the contact 1 leading to a brush 92., making electrical contact with the metal band 0 of an insulated wheel 1), which band has a revolving contact 9, against which a movable contact is yield: ingly pressed by a spring a. From the contact 0' a connection is made in any suitable way with the line-wire B. As shown, this connection is so arranged that when the contact r is in connection with the contact (7 the line is completed through these parts and a worm t and gear a to the shaft 4* and brush w, constituting part of the conductor 0, thus making a complete shunt around the resistance-box D for throwing a shunt-current through the magnets m when the controller E is in its inactive position and the contacts I] and r are engaged, such shunt being open circuited whenever the controller is moved to close the local circuit C and also whenever the contacts (1 and r are separated. The power device K moves the movable part of the fuse or cut-out necessary to restore a burned-out or cut-out circuit, as the movable contact H. It also terminates such movement and retains the contact H in engagement with the adjacent contact J under tension in the construction shown, preferably consisting in construction of the following details:

The magnets a: attract an armature u, carried by an oscillating lever .2, which is fulcrumed to oscillate on a spindle a. pivoted in a binding-post Z). Outward movement of the lever 2 is checked by a stop a, to which is connected the wire j, so that when the magnet is deenergized' and the lever is in contact with the stop electrical communication extends through the wire i, binding-post l1, spindle 0/, lever .2, stop 0, and wire 1, and when the magnet is energized the attraction of the armature swings the lever away from the stop, and thus breaks such connection, whereupon the lever may fall back and again contact with the stop to again complete the connection and energize the magnet. This device acts as a rheotome, giving rapid reciprocating movement to the end of the lever.

Near the magnetis a shaft L, revolving in bearings (Z, to which shaft is fixed a ratchetwheel M, locked against reverse motion by a pawl N and fed forwardly by a movable pawl O, which is carried by a lever P, fulcrumed to oscillate on the shaft and connected by an insulating connecting-link Q with the lever The lever P has a short arm R, against which a spring S reacts for returning the lever when the armature is released. The armature oscillates the lever rapidly, and the pawl O feeds the ratchet-wheel and shaft around at a slow speed, which may be graduated in any way by a speedcontroller, as by controlling the throw of the armaturelever by a screw (1' or otherwise. ()n the shaft the insulated wheel 0 is fixed, and a sleeve T is feathered so as to be axially adjustable, which sleeve carries the contact '1' and the worm f; and is pressed toward the contact 11 by the spring s. The worm t meshes with the worm-gear a, fixed on the shaft 1:, and turns this gear in the direction of the arrow thereon in Fig. The movable contact H moves with the gear until the contact is arrested, which prevents further movement of the gear, whereupon continued movement of the ratchet-wheel M causes the worm to feed ITO itself back and compress the spring 8 until the contacts and 17 are separated, which breaks the shunt-circuit and throws the device K out of operation. The tension of the spring 8, exerted through the worm and gear, serves to press the movable contact H against the adjacent one of the contacts J, thus completing the connection through the local circuit 0. Should the fuse'then in circuit blow out, this connection will at once be broken, and the spring 8 will start movement of the contact H and will push the sleeve to the right in Fig. 3 until the contacts q and 7' come together, the terminal J being turned to allow H to pass, as shown at J Fig. 5.

K as soon as the controller E of the switch D is turned to the off position, in whichit will bridge the terminals 10 and l, thus completing the shunt.

with a succeeding one of the contacts J, thus completing the local circuit and breaking the shunt-circuit at q r, as before described.

l/Vhile it is not absolutely necessary in all 7 than that ofmaximum resistance or of a predetermined resistance.

I prefer to indicate a permanent short circuit and toprevent an indiscriminate blowing out successively ofall the fuses in such a case by'means serving to prevent renewal 'of the local circuit in certain contingencies. As sh own,1 prevent automatic introduction of special manipulation, so that if two'fuses blow out the operator can manually control installation of the next fuse, and if it blows out he will know there isa permanent short circuit, so that he can find where this is and remedy it without blowing out all the fuses. This may be done in any suitable way; but I prefer to put a stop-wheel U on the shaft 4.; and to provide a stop V for engaging the wheel U at certain positions of the contact H. As

shown, the 'wheel has faces f f f, and f and the stop has a bolt pressed inwardly by a spring It and drawn outwardly by a handle 2'. The end ofsuch bolt rides on the periphery of the wheel U and comes into the path of an approaching one of the faces thereof, arresting movement of the wheel and its shaft 4) and the contact H whenever one of the faces of the wheel strikes the end of the bolt. These faces are so located that when the movable contact is released by the burning out of one fuse for example, that connected to the contact J the contact H can move freely into engagement with the contact J but when the contact H is released by burning out of the fuse Then the shunt-cir cuit will be in condition to operate the device x The deviceK will then operate to i move the contact H into electrical connection connected to contact. J t the contact H will'be arrested between the contact J and the contact J The operator will'thus know from the fact that the movable contact did not reach the adjacent contact J that two fuses'have been burned out and that he must look for a short circuit. If in doubt of this, he will pull the bolt V and release the wheel U and watch to see if the next fuse burns out when the contact H makes connection with the contact J In the construction shown if this fuse burns out he can arrest the contact H by inserting a stop-pin W in any of the stop-holes j, and on finding and remedying the short circuit he can remove this pin, thus permitting the contact H to travel on to the next one of the series of contacts J.

I prefer to solder the fuses to notched plates Z, which are removably clamped to the terminals g and J by screws m, so that the fuses can be'applied and removed as easily as in any ordinary fuse-box.

In operation the device will automatically restore an automatically-broken circuit within a predetermined time and under predetermined conditions, thus affording all the protection of the present fuse or cut-out provisions, while avoiding all the inconvenience and delay now incident to restoring cut-out circuits. For trolley-cars the motorman will not be compelled to leave his station to replace; a fuse, and in lighting'systems there will be practically no delay between the time a fuse burns out and the time the other is automatically installed. The device can be located where desired and operated and-installed in any suitable way.

In the operation of the power device K an I I j appreciable interval of time is consumed, so more than two fuses in succession without as to allow'of a readjustment of conditions on the line, so that the new fuse is not introduced until the overload has been probably withdrawn.

It will be'seen thatmyinvention provides improvements which can be variously and advantageously availed of, and it will be understood that I do not limit myself to any particular details of construction, combination of parts, method of installation, or means of operation in carrying out my invention.

In the modification shown in Figs. 5 and 6 a springmotor A is used for driving the spindle c, this motor consisting of a simple clockwork, which may be controlled in its speed of operation by an ordinary governor in, so as to obtain the necessary interval of time between the destruction of one fuse and the insertion of the next. The whole device as here shown is inclosed in a casing B to avoid danger of fire from the burning of the fuses. In this construction, which is designed for lighting systems, the means for controlling operation of the automatic fuse-box by the switch or resistance box of the local circuit are omitted, and the tension of the spring-barrel of the clockwork is relied on to hold the movable contactH against the adjacent one of the series of contacts J. In other respects than here pointed out this construction is substantially identical with that before described, and the parts are respectively designated by the same letters of reference, except that I prefer to use here a connection for operating the device without the necessity of going directly to it, which may be done in any manner as, for example, by a bridge-shunt 1), controlled by a springswitch X and energizing a magnet Y, the armature Z of which pulls the bolt V in order to release the wheel U, as seen in Fig. 5. This enables a motorman to operate the fuse-box from the car-platform. In a lighting, telephonic, or telegraphic, or other circuit this connection may be placed anywhere desired.

It will be seen that with my invention a fuse can be replaced without stopping a car and without requiring any special skill or knowledge.

Stops q are provided to limit movement of the contacts J. The front board r and the back board 8 may be of insulating material and connected by pillars t"; The magnets in or Y constitute a desirable resistance in their shunt-circuits. Reverse movement of the contact H in Fig. 5 rewinds the motor'A.

What Tclaim is 1. In electrical devices, the combination with an electrical conductor, of a plurality of cut-outs, a main switch, and means controlled by the opening of said switch for automatically introducing one of said cut-outs into said conductor when a preceding cut-out has operated to break the circuit through said conductor.

2. The combination with the terminals of an electrical conductor and a plurality of fuses, of a movable contact constituting part of said conductor and movable to successively introduce different fuses into electrical connection with said terminals, a main-switch lever and means operated by the movement of said. 1e:

ver to the off position for so moving said movable contact.

8. The combination with the terminals of an electrical conductor and a plurality of fuses, of a movable contact constituting part of said conductor and movable to successively introduce different fuses into electrical connection with said terminals, a main-switch lever and means operated by the movement of said lever to the off position for so moving said movable contact, and means limiting the number of successive introductions in case of a permanent short circuit.

4. A plurality of fuses, in combination with means for automatically introducing one of said fuses into electrical connection with an electrical conductor when the electrical connection of another of said fuses therewith ceases, and means independent of the strength of the current for automatically preventing such introduction under predetermined conditions.

5. In electrical devices, the combination with an electrical conductor, of a plurality of cut-outs, a main-switch lever, and means operated by turning said lever to the off position for automatically introducing one of said cutouts into said conductor when a preceding cut out has operated to break the circuit through said conductor, and means for preventing the automatic introduction of more than a determined number of cut-outs in succession without special manipulation.

6. A plurality of fuses, in combination with means for automatically introducing one of said fuses into electrical connection with an electrical conductor when the electrical connection of another of said fuses therewith ceases, and means mechanically and automatically preventing such introduction.

7. A plurality of fuses, in combination with means for automatically introducing one of said fuses into electrical connection with an electrical conductor when the electrical connection of another of said fuses therewith ceases, means for preventing the automatic introduction of more than a determined number of fuses in succession without special manipulation, and manually-operated means preventing such introduction.

8. The combination with binding-posts, of

a plurality of fuses electrically connected to one of said posts, a movable conductor electrically connected to the other of said posts, a rheotome operated by the current for moving said movable conductor to complete electrical connection between said posts, first through one of said fuses and afterward through another of said fuses, a main switch, and means for operating said rheotomc on the opening of said main switch. 9. The combination with a plurality of fuses, of a movable contact H. mechanism for automatically moving said contact to said fuses in succession, a spindle o for said contact, a wheel U having stop-faces fewer in number than the number of fuses and controlling movement of said contact, and a stop V for said wheel.

10. The combination with an electrical circuit and a plurality of fuses, of a main switch and electrically-operated means automatically introducing one fuse into said circuit after another fuse has burned out and said main switch has been opened.

11. The combination with an electrical circuit and a switch for opening and closing said circuit, of a plurality of fuses, and means controlled bysaid switch for automatically introducing one fuse into said circuit after another fuse has burned out.

12. The combination with a main circuit, a shunt-circuit and a switch for opening and closing said shunt-circuit, of a plurality of fuses and means controlled by said switch for automatically introducing one fuse into said main circuit after another fuse has burned out.

13. In an electrical circuit, an automatic fuse-replacer, in combination with a resistance-boX switch for opening and closing said circuit, said switch controlling operation of said replacer.

14:. The combination with a circuit C, of a shunt i, an electrical power device K, a plurality of fuses, means operated by said device for automatically introducing one fuse into said circuit after another fuse has been cut out, a main switch, and means for operating said power device K on the opening of said main switch.

15. In an automatic cut-out, the combination with terminals and means for making my name in the presence of two subscribing 3 witnesses.

WILLIAM MOELROY.

l/Vitnesses:

THOMAS F. WALLACE, FRED WHITE. 

